Treatment of rayon



Patented June 10, 1941 TREATMENT OF RAYON James F. Corbett, Lowell,

and Kenneth H.

Barnard, Andover, Mass., assignors to- Pacific Mills, Lawrence, Mass, acorporation of Massachusetts No Drawing. Application September 20, 1939,Serial No. 295,786

4Claims.

This invention relates to a new method of treating rayon cloth,resulting in a new fabric' and a method of producing it. The fabric is,in substance, plissd rayon.

Plissd cotton is well known, but so far as we are aware, rayon plissd inthe usual way, when washed or stretched, will at once lose its crinkledeffect. The product of our invention will not lose its pliss charactereven after repeated washings gr the stretching which an ordinary garmentsufers.

Rayon'cloth, which may be either spun or filament type rayon, which hasbeen bleached, dyed or printed in the usual maner, is first run througha padding solution in a hydraulic mangle at 13 to 15 tons pressure. Thepadding solution contains a urea formaldehyde resin solution of thepenetrative type, of a low degree of polymerization. Suitable resin maybe made by mixing 60 lbs. formaldehyde 30 lbs. urea 2 lbs. 10 oz. aquaammonia 30 Beaum This is heated to the boil for one minute in a stilland then diluted with cold water, by running it into 92pounds of water.The catalyst is then added, which may be one gallon of a saturatedammonium dihydrogen phosphate solution (NI-Ia) H2PO4.

This mixture is preferably made up fresh for each batch of cloth andafter the cloth has been padded through it, the cloth is dried on atenter at a speed of 30 to 50 yards per minute, depending on the weightof the cloth.

The resin treated cloth is then baked on a festoon type dryer in orderto set or polymerize the resin and make it water insoluble. This bakingis done by heating the treated cloth to 300 F. for three minutes. Anyextraneous matter or unset resin is washed out and the cloth neutralizedwith a warm soda ash solution. The cloth is finally dried on the tenterframe to the proper width for the subsequent pliss printing operation.

The rayon cloth which has been treated with the urea formaldehyde resinas above described is then run through a suitable pliss printing machinewhich may be like those well known for plissing cotton. We prefer toprint the cloth machine is approximately 50 yards per minute. The clothis then passed directly through a steam chamber containing a saturatedsteam atmosphere. The caustic soda contained in the gum mixture causesthe cloth to crinkle up, iving the pliss effect. In order to develop thepliss to its full extent, the slightly moist cloth after passing throughthe steam chamber, should be allowed to stand loosely in boxes for atleast two or three hours.

The cloth is then run through a series of reel washers in order toremove all excess caustic soda and is finally centrifuged to removeexcess water and dried on a festoon dryer and then framed to itsfinished width.

The above described process is the so-called direct caustic printing forplissing cotton goods, but the rayon can also be plissd by othermethods. For example, the resin treated cloth as previously described,can be printed with a resist gum and, after drying the cloth, thenpadded through a strong caustic soda solution.

Still another method for plissing the resin treated rayon cloth is bythe two roller method of caustic printing. In this case, one roll printsparallel stripes of resist gum while the other prints the caustic soda,the two rolls being so fitted that the caustic stripe falls betweenalternate stripes of resist gum.

These alternate methods are well known among textile printers forplissing cotton cloth, but we find that the so-called direct method ofcaustic printing is the most satisfactory for producing a with aprinting mixture containing British gum or other thickener and strongcaustic soda. We have found suitable for rayon, a mixture containing 127lbs. of Corn Products Companys #187 British gum which has beenpreviously boiled up to a volume of 200 gallons with 94 Tw. causticsoda. The speed through the printing crinkle on rayon.

It is believed that drawings are not necessary to the description of thepresent invention, since machines suitable for carrying out thetreatment are well known to those familiar with the art.

We claim:

1. The method of making a crinkled rayon fabric which comprises paddingthe clothwith a fabric which consists of padding the cloth with a ureaformaldehyde solution which will penetrate the fibres of the cloth,squeezing the cloth to force the resin into its fibres, setting theresin by heat, washing the cloth and then printing British gum andcaustic soda on selected areas only of the cloth, steaming the cloth andwashing 2 aaaa'mr out the caustic soda and excess of British sum, togive the cloth a pliss eflect.

3. The treatment of rayon fabric to impart a pliss effect thereto whichcomprises applying to the entire fabric a urea formaldehyde resin of thepenetrative type, rendering said resin insoluble within and throughoutthe fabric, and applying caustic to selected areas of the resin treatedfabric.-

a. The treatment of rayon fabric which comprises applying to the entirefabric a urea form-= aldehyde resin, setting said resin within thefabric by heat, printing caustic soda on selected areas only of thecloth and washing the cloth, whereby a pliss eflect is imparted to thecloth.

JAMES F. CORBETT. KENNEIH H. BARNARD.

